Continue clinico-pathological studies of diseased corneas removed at the time of keratoplasty. Of particular interest are concerns with herpetic disease, corneal edema and vitreous contact. Continue studies on the morphological changes in donor cells in vitro and the participation of T lymphocytes in graft reaction. Morphological studies of corneal changes induced by intraocular lenses in humans (pathological tissue removed at the time of keratoplasty) and in experimental animals. Study of implants used clinically by scanning electron microscopy.